Health & Science
Mars’ toxic surface
Researchers hoping to find alien life on the surface of Mars may have to dig considerably deeper for evidence of bacteria or other microbes, a new study shows. The Red Planet’s landscape is rife with reactive chemical compounds made of chloride and oxygen, known as perchlorates—a potential energy source for bacteria, which appears to increase the planet’s habitability. Because of Mars’ thin atmosphere, however, the planet is constantly bombarded with solar radiation; when perchlorates, iron oxides, and hydrogen peroxide found there are bathed in UV rays, researchers found, they form a “toxic cocktail.” Lab experiments showed this lethal mixture wiped out Bacillus subtilis, a type of bacteria that often contaminates spacecraft, within 30 seconds. These findings don’t obliterate all hope of discovering life on Mars. A more hospitable environment with lower radiation levels may lie some 6 feet below ground, PopularScience.com reports. “There’s a whole potential subsurface habitat to be explored,” says the study’s lead author, Jennifer Wadsworth. “At those depths, it’s possible Martian life may survive.”
Generosity breeds contentment
By definition selflessness, like virtue, is its own reward. But new research reveals altruism offers some personal perks, as well. Even a mere pledge to help others can trigger changes in the brain that produce a warm glow of happiness and contentment, an international team of psychologists found. The researchers told 50 people they would be given $100 over the course of four weeks. Half were instructed to keep the money for themselves. The remaining subjects were asked to spend the money on other people and describe how they would use it. Next, the participants’ brains were scanned as they considered various giving scenarios, which pitted their own interests against recipients of their generosity. The brain images revealed that selfless acts of giving triggered increased activity and connectivity in the temporoparietal junction and the ventral striatum––regions associated with reward, pleasure, and happiness. Even small acts of generosity had significant effects. “You don’t need to become a self-sacrificing martyr to feel happier,” University of Zurich researcher Philippe Tobler tells PsychCentral.com. “Just being a little more generous will suffice.”
Drink coffee, live longer
People who rely on a cup of joe to wake up or power through the day could be adding years to their lives. Two sweeping new studies reveal that a coffee habit could boost longevity by reducing the risk of death from heart disease, stroke, cancer, diabetes, and kidney disease. “If you like to drink coffee, drink up,” researcher Veronica Setiawan of the University of Southern California tells ScienceDaily.com. “If you’re not a coffee drinker, then you need to consider if you should start.” Setiawan’s team examined data on nearly 186,000 adults of various races and ethnicities. The results showed mortality risk dropped 12 percent for those who drank just one cup of coffee each day while two to three cups brought even better odds—18 percent. Another study analyzed the link between coffee and prolonged life span among more than 500,000 Europeans who were followed for about 16 years. Men who drank the most coffee had a 12 percent lower risk of early death. For women, the risk dropped 7 percent. Coffee contains a complex mixture of powerful antioxidants, but it’s unclear what accounts for the drink’s benefits. Apparently it’s not the caffeine—in both studies, researchers found decaf just as effective.
Health scare of the week
Poor sleep tied to Alzheimer’s
Adults with normal thinking and memory skills who have trouble sleeping may be at greater risk for Alzheimer’s disease, a new study shows. Researchers asked 101 older people with genetic risk factors for the degenerative brain disease to complete a sleep questionnaire. Samples of participants’ spinal fluid revealed those reporting poor sleep quality had more biological markers of Alzheimer’s, including buildups and tangles of toxic proteins, such as beta-amyloid and tau, as well as brain-cell damage and inflammation, The New York Times reports. “Not everyone with sleep problems is destined to develop Alzheimer’s disease,” says study author Barbara Bendlin of the University of Wisconsin. “We’re looking at groups of people, and over the whole group we find the association of poor sleep with the markers of Alzheimer’s.” The precise link is unclear. Previous studies suggest the brain “cleans house” overnight, clearing out harmful toxins, and sleep loss could disrupt this protective process.
British Antarctic Survey, NASA/JPL-Caltech/MSSS, Getty ■